import uuid
from datetime import datetime, timezone
from typing import Callable

from fastapi import APIRouter, Body, Request, status
from fastapi.responses import JSONResponse
from pydantic import BaseModel, SecretStr

from openhands.core.logger import openhands_logger as logger
from openhands.events.action.message import MessageAction
from openhands.events.stream import EventStreamSubscriber
from openhands.integrations.github.github_service import GithubServiceImpl
from openhands.runtime import get_runtime_cls
from openhands.server.auth import get_github_token, get_idp_token, get_user_id
from openhands.server.data_models.conversation_info import ConversationInfo
from openhands.server.data_models.conversation_info_result_set import (
    ConversationInfoResultSet,
)
from openhands.server.session.conversation_init_data import ConversationInitData
from openhands.server.shared import (
    ConversationStoreImpl,
    SettingsStoreImpl,
    config,
    conversation_manager,
    monitoring_listener,
)
from openhands.server.types import LLMAuthenticationError, MissingSettingsError
from openhands.storage.data_models.conversation_metadata import ConversationMetadata
from openhands.storage.data_models.conversation_status import ConversationStatus
from openhands.utils.async_utils import (
    GENERAL_TIMEOUT,
    call_async_from_sync,
    wait_all,
)

app = APIRouter(prefix='/api')
UPDATED_AT_CALLBACK_ID = 'updated_at_callback_id'


class InitSessionRequest(BaseModel):
    selected_repository: str | None = None
    selected_branch: str | None = None
    initial_user_msg: str | None = None
    image_urls: list[str] | None = None


async def _create_new_conversation(
    user_id: str | None,
    token: SecretStr | None,
    selected_repository: str | None,
    selected_branch: str | None,
    initial_user_msg: str | None,
    image_urls: list[str] | None,
    attach_convo_id: bool = False,
):
    monitoring_listener.on_create_conversation()
    logger.info('Loading settings')
    settings_store = await SettingsStoreImpl.get_instance(config, user_id)
    settings = await settings_store.load()
    logger.info('Settings loaded')

    session_init_args: dict = {}
    if settings:
        session_init_args = {**settings.__dict__, **session_init_args}
        # We could use litellm.check_valid_key for a more accurate check,
        # but that would run a tiny inference.
        if (
            not settings.llm_api_key
            or settings.llm_api_key.get_secret_value().isspace()
        ):
            logger.warn(f'Missing api key for model {settings.llm_model}')
            raise LLMAuthenticationError(
                'Error authenticating with the LLM provider. Please check your API key'
            )

    else:
        logger.warn('Settings not present, not starting conversation')
        raise MissingSettingsError('Settings not found')

    session_init_args['github_token'] = token or SecretStr('')
    session_init_args['selected_repository'] = selected_repository
    session_init_args['selected_branch'] = selected_branch
    conversation_init_data = ConversationInitData(**session_init_args)
    logger.info('Loading conversation store')
    conversation_store = await ConversationStoreImpl.get_instance(config, user_id)
    logger.info('Conversation store loaded')

    conversation_id = uuid.uuid4().hex
    while await conversation_store.exists(conversation_id):
        logger.warning(f'Collision on conversation ID: {conversation_id}. Retrying...')
        conversation_id = uuid.uuid4().hex
    logger.info(f'New conversation ID: {conversation_id}')

    repository_title = (
        selected_repository.split('/')[-1] if selected_repository else None
    )
    conversation_title = f'{repository_title or "Conversation"} {conversation_id[:5]}'

    logger.info(f'Saving metadata for conversation {conversation_id}')
    await conversation_store.save_metadata(
        ConversationMetadata(
            conversation_id=conversation_id,
            title=conversation_title,
            github_user_id=user_id,
            selected_repository=selected_repository,
            selected_branch=selected_branch,
        )
    )

    logger.info(f'Starting agent loop for conversation {conversation_id}')
    initial_message_action = None
    if initial_user_msg or image_urls:
        user_msg = (
            initial_user_msg.format(conversation_id)
            if attach_convo_id and initial_user_msg
            else initial_user_msg
        )
        initial_message_action = MessageAction(
            content=user_msg or '',
            image_urls=image_urls or [],
        )
    event_stream = await conversation_manager.maybe_start_agent_loop(
        conversation_id, conversation_init_data, user_id, initial_message_action
    )
    try:
        event_stream.subscribe(
            EventStreamSubscriber.SERVER,
            _create_conversation_update_callback(user_id, conversation_id),
            UPDATED_AT_CALLBACK_ID,
        )
    except ValueError:
        pass  # Already subscribed - take no action
    logger.info(f'Finished initializing conversation {conversation_id}')

    return conversation_id


@app.post('/conversations')
async def new_conversation(request: Request, data: InitSessionRequest):
    """Initialize a new session or join an existing one.

    After successful initialization, the client should connect to the WebSocket
    using the returned conversation ID.
    """
    logger.info('Initializing new conversation')
    user_id = get_user_id(request)
    gh_client = GithubServiceImpl(
        user_id=user_id,
        idp_token=get_idp_token(request),
        token=get_github_token(request),
    )
    github_token = await gh_client.get_latest_token()

    selected_repository = data.selected_repository
    selected_branch = data.selected_branch
    initial_user_msg = data.initial_user_msg
    image_urls = data.image_urls or []

    try:
        # Create conversation with initial message
        conversation_id = await _create_new_conversation(
            user_id,
            github_token,
            selected_repository,
            selected_branch,
            initial_user_msg,
            image_urls,
        )

        return JSONResponse(
            content={'status': 'ok', 'conversation_id': conversation_id}
        )
    except MissingSettingsError as e:
        return JSONResponse(
            content={
                'status': 'error',
                'message': str(e),
                'msg_id': 'CONFIGURATION$SETTINGS_NOT_FOUND',
            },
            status_code=status.HTTP_400_BAD_REQUEST,
        )

    except LLMAuthenticationError as e:
        return JSONResponse(
            content={
                'status': 'error',
                'message': str(e),
                'msg_id': 'STATUS$ERROR_LLM_AUTHENTICATION',
            },
            status_code=status.HTTP_400_BAD_REQUEST,
        )


@app.get('/conversations')
async def search_conversations(
    request: Request,
    page_id: str | None = None,
    limit: int = 20,
) -> ConversationInfoResultSet:
    conversation_store = await ConversationStoreImpl.get_instance(
        config, get_user_id(request)
    )
    conversation_metadata_result_set = await conversation_store.search(page_id, limit)

    # Filter out conversations older than max_age
    now = datetime.now(timezone.utc)
    max_age = config.conversation_max_age_seconds
    filtered_results = [
        conversation
        for conversation in conversation_metadata_result_set.results
        if hasattr(conversation, 'created_at')
        and (now - conversation.created_at.replace(tzinfo=timezone.utc)).total_seconds()
        <= max_age
    ]

    conversation_ids = set(
        conversation.conversation_id for conversation in filtered_results
    )
    running_conversations = await conversation_manager.get_running_agent_loops(
        get_user_id(request), set(conversation_ids)
    )
    result = ConversationInfoResultSet(
        results=await wait_all(
            _get_conversation_info(
                conversation=conversation,
                is_running=conversation.conversation_id in running_conversations,
            )
            for conversation in filtered_results
        ),
        next_page_id=conversation_metadata_result_set.next_page_id,
    )
    return result


@app.get('/conversations/{conversation_id}')
async def get_conversation(
    conversation_id: str, request: Request
) -> ConversationInfo | None:
    conversation_store = await ConversationStoreImpl.get_instance(
        config, get_user_id(request)
    )
    try:
        metadata = await conversation_store.get_metadata(conversation_id)
        is_running = await conversation_manager.is_agent_loop_running(conversation_id)
        conversation_info = await _get_conversation_info(metadata, is_running)
        return conversation_info
    except FileNotFoundError:
        return None


@app.patch('/conversations/{conversation_id}')
async def update_conversation(
    request: Request, conversation_id: str, title: str = Body(embed=True)
) -> bool:
    conversation_store = await ConversationStoreImpl.get_instance(
        config, get_user_id(request)
    )
    metadata = await conversation_store.get_metadata(conversation_id)
    if not metadata:
        return False
    metadata.title = title
    await conversation_store.save_metadata(metadata)
    return True


@app.delete('/conversations/{conversation_id}')
async def delete_conversation(
    conversation_id: str,
    request: Request,
) -> bool:
    conversation_store = await ConversationStoreImpl.get_instance(
        config, get_user_id(request)
    )
    try:
        await conversation_store.get_metadata(conversation_id)
    except FileNotFoundError:
        return False
    is_running = await conversation_manager.is_agent_loop_running(conversation_id)
    if is_running:
        await conversation_manager.close_session(conversation_id)
    runtime_cls = get_runtime_cls(config.runtime)
    await runtime_cls.delete(conversation_id)
    await conversation_store.delete_metadata(conversation_id)
    return True


async def _get_conversation_info(
    conversation: ConversationMetadata,
    is_running: bool,
) -> ConversationInfo | None:
    try:
        title = conversation.title
        if not title:
            title = f'Conversation {conversation.conversation_id[:5]}'
        return ConversationInfo(
            conversation_id=conversation.conversation_id,
            title=title,
            last_updated_at=conversation.last_updated_at,
            created_at=conversation.created_at,
            selected_repository=conversation.selected_repository,
            status=ConversationStatus.RUNNING
            if is_running
            else ConversationStatus.STOPPED,
        )
    except Exception as e:
        logger.error(
            f'Error loading conversation {conversation.conversation_id}: {str(e)}',
        )
        return None


def _create_conversation_update_callback(
    user_id: str | None, conversation_id: str
) -> Callable:
    def callback(*args, **kwargs):
        call_async_from_sync(
            _update_timestamp_for_conversation,
            GENERAL_TIMEOUT,
            user_id,
            conversation_id,
        )

    return callback


async def _update_timestamp_for_conversation(user_id: str, conversation_id: str):
    conversation_store = await ConversationStoreImpl.get_instance(config, user_id)
    conversation = await conversation_store.get_metadata(conversation_id)
    conversation.last_updated_at = datetime.now(timezone.utc)
    await conversation_store.save_metadata(conversation)
